Alan Yentob has spent weeks as the object of increasingly serious criticism, up to and including calls for his head. The charge was grave: producers had made it look as if the BBC's creative director and presenter of the flagship arts show Imagine was present at interviews he did not conduct. Calls for Yentob to quit were raised again over the weekend as the BBC1 controller Peter Fincham resigned over a separate, but related, issue of trust in TV.

It turns out that, as Will Wyatt was working on his investigation into "Crowngate", staff on Yentob's arts programme Imagine were conducting a trawl into "Noddygate". The results, we can reveal today, are stark. In all of the shows, in the four years since Imagine began, fake "noddies" were inserted into precisely none of them. Not one.

So how did it happen then that such a damaging allegation was allowed to gain so much traction? "It's all my own fault . . . it was foolish of me to respond in that fashion. I did not want to say no to something that might have been yes."

So when the media asked whether he had allowed noddies to be used to make it look as if he had been where he hadn't, he said possibly, probably and even suggested it was quite likely because he couldn't remember and didn't want to be caught fibbing? Well, baldly, the answer to that question is yes. So shouldn't he have checked? "Yes . . . I do think I should have checked." So why on earth didn't he?

Original passion

And it's here that the story becomes altogether much more interesting. I should say at this point that I have known Yentob for some 25 years and have worked with him quite closely - when he was controller of BBC1 in particular. Yentob started his BBC career as a general trainee but swiftly found his place in film-making. That and the arts were always his passions, and, in truth, they still are.

And in spite of having made his whole career at the BBC and risen over time to almost the very top of the corporate management pole, it is his undisputed talents as a programme-maker that have underpinned his achievements and which - when other things haven't quite worked out - he's been able to fall back on. Even his current position as creative director for the whole of the BBC appeared fashioned to keep him and his formidable, some would say totemic, creative reputation inside the BBC, at the same time as taking most of his direct management responsibilities away. So as our discussion of "Noddygate" progresses I begin to realise that, although he has the title of a very high ranking corporate executive, the person I'm really talking to is Alan Yentob the film-maker - ego attached - whose original passion has been reawakened by the opportunity to produce and present his own BBC1 arts strand Imagine. And it's that realisation that begins to make sense of what otherwise looks like a spectacular PR own goal. So again, why did he say he might have done noddies as alleged?

"Because I make arts programmes and we're always using cutaways or something. I knew I wouldn't have done it routinely and I assumed people would understand - particularly because the films I've done have been quite narrative, quite playful . . . programmes are constructed and made and I didn't think anyone would challenge me about that," he says.

In other words Alan Yentob, programme-maker, doesn't imagine for a second that anyone could seriously be suggesting that he might have acted unethically. In a nutshell he couldn't be sure it hadn't happened but was certain he could explain it if it had. He goes further, seeing himself as "defending the principle that making programmes is not the same as real life - why do we cut out the questions? Edit together the best bits?" All techniques he passionately believes are basic to film-making and effective storytelling and not in any meaningful sense deceptive.

But in seeing this in such a personal way - he was filming with Damien Hirst in New York at the time the story broke - he now acknowledges that in corporate and political terms he's really put his foot in it. "I didn't take on board that in this debate - where I think there are serious issues - I would be misunderstood. It stresses me to think that people might imagine I'd taken liberties with the truth - which is absolutely not true."

So what does he have to say to the thousands of BBC staff who he now recognises have also been labouring with the consequences of his original misjudgment - at what is, by any standards, a very difficult time for the whole organisation? "I'm sorry - I hope you understand why I did it. I wanted to be open and undefensive - it turned out that was not the way it was interpreted. It led some people licence to think the worst of me, and it led others to think that perhaps it was a licence to do whatever you like. I apologise but I'd like to pick up that debate."

Trust and honesty

And there's no doubt that he has genuine fears for the future of TV as a creative medium, and that in the current environment of such heightened sensitivity great damage might be done. "They're very precious these things - the ability to tell stories and to find ways to do that which engage our audiences but don't mislead them; where sometimes we use techniques of artifice to enhance those shows but not to deceive."

He says there needs to be an open debate both within the BBC and beyond - one, importantly, fully open to audiences too - about where lines should be drawn and under what circumstances they might properly be crossed. This is all the more necessary, he says, after "10 years of genre bending and 'reality' TV" which have led to what he describes as "a laziness, a routineness about how you make programmes - you want to make them more exciting so you add a bit"; but without that context public service delights like Jamie's School Dinners simply wouldn't have happened. The debate so far, he says, has "suggested that you can't trust anyone - as if programme makers were estate agents, and that's not true. There are no more motivated people than those who work in broadcasting . . . and ultimately it is about trust and honesty."

So this week in the aftermath of "Crowngate", "Socksgate" and the rest and with "Noddygate" looking rather more noddyish than anything else, maybe now a line can be drawn and Yentob's much needed debate can actually get under way.